This invention relates to a sanitary napkin for absorbing and containing menstrual fluids.
Japanese Patent Gazette No. 2744048 discloses a sanitary napkin being convex toward a wearer""s body side and including elastic means extending transversely across an absorbent element. The elastic means is secured under tension to the napkin at two or more points thereon.
Japanese Patent Application Disclosure Gazette (Kokai) No. Hei2-11138 describes a sanitary napkin adapted to be curved convexly upward as the napkin is put on a wearer""s body and including an absorbent core which is provided all over its lower side with a deformation element having a high bending stiffness. The deformation element may be provided, for example, in the form of moldings of polyethylene foam.
The sanitary napkin disclosed in the Japanese Patent Gazette No. 2744048 is disadvantageous in that the convex shape obtained by the elastic means depends on the individual sanitary napkins and is hardly uniformed in a predetermined shape. Most of the absorbent element principally comprise pulp fibers or a mixture of such pulp fibers and superabsorptive polymer particles. Such absorbent element has not necessarily an inter-fiber structure and a rigidity which are suitable for describing the convex shape. In addition, such absorbent element is often uneven in its density and therefore it can not be ensured that a substantially uniform convex shape is described.
The sanitary napkin described in the Japanese Patent Application Disclosure Gazette (Kokai) No. Hei2-11138 certainly makes it possible to obtain the uniform convex shape using the deformation element. However, the presence of the deformation element inevitably makes the napkin relatively bulky and this may create a feeling of discomfort against a wearer.
It is an object of the present invention to provide a sanitary napkin in which a protuberant region on an upper side of an absorbent core can be uniform in a predetermined shape without making the napkin bulky.
According to the present invention, there is provided a sanitary napkin comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed therebetween, the sanitary napkin having a contour defined by first and second ends extending in a transverse direction of the napkin and first and second side edges extending continuously from the first and second ends, respectively, in a longitudinal direction of the napkin, the core being formed in a transverse middle thereof with a protuberant region convexly curved toward a body side of the napkin.
In such sanitary napkin, the present invention is characterized by that the protuberant region is formed by bending the core substantially in an inverted V-shape along a first groove extending substantially in alignment with a center line dividing the core in two transversely thereof and being concave from a lower side toward an upper side of the core, and along a pair of second grooves extending in the longitudinal direction in vicinities of the side edges of the core and being concave from the upper side toward the lower side of the core, and the core is provided on the lower side thereof with a plurality of elastic members secured thereto under tension and obliquely extending across the first groove.
According to one embodiment of the present invention, the plurality of elastic members intersect each other.
According to another embodiment of the present invention, the plurality of elastic members intersect the first groove at an angle in a range of 20xcx9c70xc2x0.
According to still another embodiment of the present invention, the core is provided on the lower side thereof with a hydrophobic panel adapted to be bent in an inverted V-shape substantially in conformity with the inverted V-shape of the core.
According to further another embodiment of the present invention, at least one of the plurality of elastic members extends in parallel to the center line of the core under tension between a longitudinal middle of said napkin and the first end and/or the longitudinal middle and the second end, and the napkin is folded with the topsheet lying inside along an imaginary line or imaginary lines extending transversely of the napkin orthogonally to sections of the elastic member(s) extending in parallel to the center line so that the napkin is packaged in such a folded state.